Some useful integer arrays for the teaching of generalization skills

Teachers of first-year college mathematics and engineering courses must often spend considerable time reviewing material originally taught in high school. Instead of this being a mere exercise in repetition, this article suggests that such a review can enrich and revitalize by unifying some of the subjects that need to be re-taught. In the example presented, the subjects in question are absolute values, graphs and solutions of equations, and domains of definition. These are unified by the problem of finding an analytic expression for a square and triangle and their interiors. In the course of the development, basic notions such as the additive property of areas and convexity are introduced. The approach presented in the article was tried with secondary school teachers participating in professional development workshops and with students at a technical college; the teachers and students responded enthusiastically to the material.     

Proposition of a compensated pixelwise calibration for photonic infrared cameras and comparison to classic calibration procedures: Case of thermoelastic stress analysis

In this paper, we propose a compensated pixelwise calibration that integrates the effects of the camera housing temperature. The results of this calibration are compared on black body images to classic two points Non Uniformity Correction based calibrations, compensated or not. It is shown that the proposed approach leads to a significant improvement in the thermal resolution with a reduction in the mean error as well as the standard deviation. The approach is finally challenged on a real case measurement focusing on thermoelasticity. The gain in terms of accuracy measurement is highlighted by comparing the proposed calibration to classic calibrations and the scope of interest of this new calibration is discussed.     

红外焦平面探测器中间层杨氏模量提取研究

为系统研究热冲击下InSb焦平面探测器的形变规律,需借助多层材料形变分析方程组求得其形变解析解。本文在分析、模拟双组份弹性材料均匀混合后其等效杨氏模量随体积分数变化趋势的基础上,借助有限元软件ANSYS对InSb焦平面探测器中间层等效杨氏模量的提取进行系统研究。分析结果表明,直接采用线弹性材料模型模拟的结果与真实材料的等效杨氏模量相去甚远,需用黏塑性模型方能给出符合实际的中间层等效杨氏模量;在InSb焦平面探测器典型结构设计中,中间层的等效杨氏模量随体积分数的演化规律可用线性方程描述,这为后续探测器结构优化提供了理论分析模型支撑。     

热红外高光谱成像技术的研究现状与展望

高光谱成像具有精细的光谱分辨能力,在热红外谱段实施高光谱成像对目标探测与识别有显著效果.与国外相比,我国在该领域的研究还相对薄弱,应用部门的研究主要基于国外数据,国内尚未有成熟的仪器.对国内外研究现状进行了详细调研,并结合目前国内已经布局的研究项目对该领域未来的发展进行了展望,对我国发展高性能空间红外光谱成像技术具有一定意义.     

基于模拟电荷法分析避雷针/ 线附近电位分布

雷暴云下方地面大气电场强度分布是影响雷电走向的重要因素之一,研究雷暴条件下避雷针/线周围电场分布对建筑物防雷具有重要意义。依据模拟电荷法的原理,建立此方法下避雷针/线周围电位分布的数学模型,并利用半径很小的半球面作为针尖的替代,来解决避雷针尖端"奇点"的问题,通过仿真作出避雷针/线的等电位面簇的图形。分析结果表明避雷针/线附近大气等电位面分布较空间其他地方密集,对应的电场强度较大。     

天线相位中心位置的计算方法

本文提出了一种天线相位中心位置的计算方法,该方法基于天线远场幅度与相位方向图,能够快速计算出天线相位中心位置。首先建立天线相位中心位置与远场相位方向图之间的模型,然后求远场相位SSD对位置偏移的偏导,得到相位SSD的最小值以及此时的位置偏移。在计算相位中心的过程中可以根据要求选取不同的幅度加权方法,在计算结束后,通过补偿后的相位方向图来比较几种加权方法的计算效果。     

计算传输线平均耦合截面积的一种高效全波方法

在功率平衡法的网络化公式应用中,精确预知腔内装载物的耦合截面积是关键,这通常依赖于混响室的实验测定.文中使用平面波角谱概念和蒙特卡罗方法来数值模拟混响室中的电磁环境,在此基础上,首次应用基于互易定理的快速全波分析方法提取了理想混响室内靠近理想导电地平面的多导体传输线的平均耦合截面积,验证了方法的正确性,并计算了单根裸线传输线、带包层传输线、双绞传输线、传输线附近有导体挡板以及多导体传输线端口的平均耦合截面积.该方法具有计算精度高、仿真速度快、适用范围广的特点.     

Anodic stripping voltammetry of antimony at unmodified carbon electrodes

Antimony is an element of significant environmental concern, yet has been neglected relative to other heavy metals in electroanalysis. As such very little research has been reported on the electroanalytical determination of antimony at unmodified carbon electrodes. In this paper we report the electrochemical determination of Sb(III) in HCl solutions using unmodified carbon substrates, with focus on non-classical carbon materials namely edge plane pyrolytic graphite (EPPG), boron doped diamond (BDD) and screen-printed electrodes (SPE). Using differential pulse anodic stripping voltammetry, EPPG was found to give a considerably greater response towards antimony than other unmodified carbon electrodes, allowing highly linear ranges in nanomolar concentrations and a detection limit of 3.9?nM in 0.25?M HCl. Furthermore, the sensitivity of the response from EPPG was 100 times greater than for glassy carbon (GC). Unmodified GC gave a comparable response to previous results using the bare substrate, and BDD gave an improved, yet still very high limit of detection of 320?nM compared to previous analysis using an iridium oxide modified BDD electrode. SPEs gave a very poor response to antimony, even at high concentrations, observing no linearity from standard additions, as well as a major interference from the ink intrinsic to the working electrode carbon material. Owing to its superior performance relative to other carbon electrodes, the EPPG electrode was subjected to further analytical testing with antimony. The response of the electrode for a 40?nM concentration of Sb(III) was reproducible with a mean peak current of 1.07?µA and variation of 8.4% (n?=?8). The effect of metals copper, bismuth and arsenic were investigated at the electrode, as they are common interferences for stripping analysis of antimony.     

Design rule of indium bump in infrared focal plane array for longer cycling life

In light of the proposed equivalent method, a three-dimensional structural modeling of InSb infrared focal plane arrays (IRFPAs) is created, and the simulated strain distribution is identical to the deformation distribution on the top surface of InSb IRFPAs. After comparing the deformation features at different regions with the structural characteristics of IRFPAs, we infer that the flatness of InSb IRFPAs will be improved with a thinner indium bump array, and this inference is verified by subsequent simulation results. That is, when the diameter of indium bump is smaller than 20 μm, the simulated Z-components of strain on the whole top surface of InSb IRFPAs is uniform, and the deformation amplitude is small. When the diameter of indium bump is larger than 28 μm, the simulated Z-components of strain increases rapidly with the thicker indium bump, and the flatness of InSb IRFPAs is worsened rapidly. According to the changing trend of deformation amplitude with diameters of indium bump, and employing element pitches normalization method, a design rule of indium bump is proposed. That is, when the diameter of indium bump is shorter than 0.4 times the element pitch, the flatness of InSb IRFPAs is in an acceptable range. This design rule was supported by different IRFPAs with different formats delivered by several main research groups for achieving a longer cycling life.     

基于kinect和unity的虚拟手抓取碰撞检测算法

针对目前碰撞检测算法效率低精度差的问题,提出了一种改进的层次方向包围盒（OBB）算法。首先通过位置关系判断虚拟手是否在物体包围球的邻近区域,然后用OBB和八叉树算法进行详细的碰撞检测,最后利用离散点到虚拟手简化面的矢量计算法实现精确的碰撞检测。实验结果表明,随着三维物体基元数目的增多,这种由粗略到精确递进的检测方式极大的提高了碰撞检测的效率和精度,具有可行性。该算法适用于任何复杂场景中刚体结构模型的碰撞检测,在运行时候不存在滞后情况,显示流畅,而且碰撞检测精度高,完全能够满足虚拟环境实时性和精确性的要求。